Pressure responsive valve

ABSTRACT

A valve which permits fluid to flow therethrough under normal pressure conditions but which closes in response to a reduction of fluid pressure in the system below a predetermined value. The valve operates to prevent the detrimental intrusion of foreign substances, such as air, dirt, vapor, oil, fumes, etc. into the system.

United States Patent [1 1 [111 3,809,117 00ta et al. 5] May 7, 1974 PRESSURE RESPONSIVE VALVE [56] References Cited [76] Inventors: Shiro Oota, 1-237, Aza U T TATES PATENTS Kukuchimae, Shimosakabe, 3,441,050 4/1969 Sanchez l37/493.6 Amagasakishi, Hyogoken; Keitaro 3,729,0l9 4/1973 Kudlaty ICU/493.6 Yonezawa, 12-9-3, Kusugaokacho, Nadaku, Kobe, Hyogoken, both of Primary Examiner-Henry T. Klinksiek Japan Assistant Examiner-Robert J. Miller [22] Filed: 7 Jan 26 1973 Attorney, Agent, or firm-Bacon & Thomas 21 Appl. No.: 326,961 [57] ABSTRACT A valve which permits fluid to flow therethrough 30 Foreign Application priority Data under normal pressure conditions but wl ich closes in Jan 3] 1972 13 an 47/115 response to a reducnon of flLllCl pressure m the system p belowa predetermined value. The valve operates to [52] U S Cl 137/493 6 prevent the detrimental intrusion of foreign sub- [51] Int CL l 16k l7/2 6 g Such as dirt fumes 58 Field of Search 137/493.6, 493.9, 493 e SYS t 12 Claims, 6 Drawing Figures 2 I 4- 43 t "I E q= Z 7* Z s fii 1 @Q na-1 j] 13 2/ ;L- 21 PATENTEDW 4 SHEEI 1 OF 2 1 PRESSURE RESPONSIVE VALVE BACKGROUND AND OBJECTS monly opened and closed by hand. It has frequently happened that the valve cock of such a valve is left open, intentionally or accidentally, especially when the content of the container is a kind unlikely to pollute air, such as oxygen or carbon dioxide. This, however, creates a detrimental condition whereby impure outside air, dirt, vapor, oil, fumes, etc. may be introduced into the container through the open valve. Owing to the impurities thus introduced, freshly-charged fluid is in danger of contamination. Ordinarily, after empty containers are collected from users, it is necessary to clean the containers with water and dry them in order to keep the inside thereof free from the foreign matter and to assure purity in the freshly-charged gas. In addition, The air remaining inside the containers must be emptied either by substitution or vacuum suction, subsequent to the cleaning operation. Consequently, time and labor are wastefully spent in the course of preparation, resulting in reduced efficiency and increased cost.

OBJECTS OF THE INVENTION The present invention aims to overcome the disadvantages pointed out above. A primary object of the invention is to provide a valve capable of automatically blocking the flow of fluid in response to a reduction of fluid pressure below a predetermined value, thereby protecting against the intrusion of impurities into a container even when the valve cock is left open.

Another primary object of the present invention is to provide a valve of relatively simple construction and of high reliability, thereby minimizing costs and improving the safety of operation.

A further primary object of the present invention is to provide a valve of small and handy size which is adapted for use in conjunction with known hand valves without occupying room in the inlet and outlet of the container.

A still further primary object of the present invention is to provide a valve with a minimum area of sealing engagement against the valve chamber, thereby eliminating the necessity to provide lubricant in this area. This prevents problems which can arise due to mixing of the lubricant or its vapor with the fluid in the system. Also,

frictional resistance by the sealing elements, e.g., sealing rings, such as would hamper the operation of valves, is avoided.

Other objects and advantages of the present invention will become apparent from the following description, drawings, and appended claims.

SUMMARY OF THE INVENTION- In accordance with the present invention a valve comprises a valve body including a valve chamber having a fluid inlet at one end and a fluid outlet at the opposite end. A first moveable valve member is slidably mounted in the upstream section of the valve chamber,

and is provided with a bore in the sliding direction. A

second moveable valve member is slidably mounted in the downstream section of the valve chamber. A first spring is located in the upstream section to back up the first valve member so that the first and second valve members are urged into sealing contact with each other by their respective first and second springs. The second valve member includes a bypass disposed outside of the sealing plane between the first and second valve members. A stop means is provided for at least one of the two valve members.

BRIEF DESCRIPTION OF THE DRAWING The invention will be more particularly described by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a valve according to the invention,

FIG. 2 is an exploded perspective view of various elements of the valve illustrated in FIG. 1,

FIG. 3 is a longitudinal section through the valve illustrated in FIG. 1, showing the disposition of various elements during the discharge of fluid,

FIG. 4 is a longitudinal section through the valve illustrated in FIG. 1, showing the disposition of various elements during re-fill of a container,

FIG. 5 is a longitudinal section through another form of valve according to the invention,

FIG. 6 is a cross-section taken along the line II-II of FIG. 5.

DETAILED DESCRIPTION OF THE DRAWING CONSTRUCTION OF THE EMBODIMENT OF FIGS. 1 AND 2 Referring to FIGS. 1 and 2, a valve body 1 has an extension 2 provided with external threads 3. These threads are provided to accept a fluid discharge pipe (not shown). Inside the extension 2, there is provided an outlet or outlet passageway 4 of relatively large diameter having internal threads 5. Within the outlet 4, a valve chamber 6 is provided. The valve chamber 6 communicates with an inlet or inlet passageway 7, which in turn is directly coupled to a container (not shown).

A valve abutment 8 is housed in the valve body 1, this valve abutment having threads 9 atone end with which the threads 5 of the outlet passageway 4 engage. The opposite end of the abutment 8 has a narrowed outside diameter, and has an annular groove 10 adjacent to the open end. Asealing ring 11 within the groove 10 is packed against the inside wall of the valve chamber 6. In the center of the abutment 8 and adjacent the threaded end thereof, a bore 12 is provided to serve as a fluid passageway. Between the opening of the bore 12 and the narrowed end, there is provided a spring chamber 13 and a check valve accommodation chamber 14. The abutment 8 has a abutting face 16 in the upstream direction, in the form of a projection as illustrated in FIG. 1. The abutment 8 is insertedly fixed in the valve body 1 with the threads 5 and 9 in mutual engagement. The end face 15 of the abutment 8 faces the upstream side of the system, and occupies half the space of the valve chamber 6. The contacting surfaces between abutment 8 and valve chamber 6 are suitably sealed.

Inside the valve chamber 6 an out-flow check valve member 18 (hereinafter referred to merely as check valve 18) is slidably mounted. Check valve 18 is disposed in the narrow end portion of the abutment 8 and, specifically, in the chamber 14 thereof. The projection 19 is disposed in a face-to-face relationship with the upstream chamber 17 of relatively large diameter. A gap 21 exists between each flat side face 20 of the check valve 18 and the inside walls of the narrow diameter chamber 14. These gaps act as passageways for fluid flow in either direction.

A counterpart in-flow check valve member 22 (hereinafter referred to merely as check valve 22) is slidably mounted in the valve chamber 6 in face-to-face relationship with check valve 18. Check valve 22 is provided with an annular packing 24 on its boss 23. The packing 24 engages with projections 16 and 19. Check valve 22 is hollow and includes a bore 25 in addition to the large diameter chamber 17 referred to above. Also, check valve 22 has an appropriate number of grooves 26 in the outside surface, the grooves being cut along the line of fluid flow. An aperture 32 is provided in the outside surface of check valve 22 to provide communication between the inside and outside thereof. Check valve 22 is mounted such that the packing 24 is in engagement with projections 16 and 19.

Check valves 18 and 22 are urged by springs 27 and 28 respectively, spring 28 being of less strength than the spring 27. Spring 27 is supported on a shoulder 29 in the inside wall 31 of the inlet passageway 7. Spring 28 is supported between check valve 18 and the inside wall 30 of the spring chamber 13. Under normal conditions, check valves 18 and 22 are kept in sealing contact with each other, thereby permitting no flow of fluid in the system.

OPERATION OF THE EMBODIMENT OF FIGS. 1 AND 2 The embodiment illustrated in FIGS. 1 and 2 is operated as follows:

When the fluid pressures in the upstream chamber 17 and in the downstream chamber 14 are equal, the check valves 18 and 22 will assume positions placing them in sealing contact with each other as illustrated in FIG. 1. In such positions, the packing 24 is held in tight contact with the abutting face 16 under the urge of the springs 27 and 28. Thus, the closure of the system prevents the flow of fluid.

When a hand cock (not shown) is opened to permit high pressure fluid to flow out of the container and into the upstream chamber 17, the weaker spring 28 easily yields. As spring 28 retracts in the downstream direction, the abutting face 19 disengages from the packing 24. Thus, fluid may now flow into the passageway 21 and thence through the outlet passageway 12. When the hand cock is closed, the fluid pressure in the upstream chamber l7 drops, thereby causing check valve 18 to return to the original position indicated in FIG. 1 under the urging of spring 28. Thus, the system is again closed with no flow of fluid. If the hand cock is left open, accidentally or intentionally, the check valve 18 will automatically close under the urge of the spring 28 in response to the reduction of fluid pressure. Thus, when the pressure in the container is reduced below a given value, the flow of fluid between the inside and outside of the system is cut off.

When the container is to be filled with fluid froma fluid supply pipe 33 (FIG. 4), the hand cock is opened to initiate flow. The inflowing fluid is first introduced into the downstream chamber 14 thereby causing the check valve 22 to retract against the force of spring 27 under the influence of the highly-pressurized fluid flowing through the bypass 21. From here, the fluid passes into the container via grooves 26, aperture 32, upstream chamber 17, and finally the inlet passageway 7. After the container has been filled with fluid, the hand cock is closed, and the supply pipe 33 is removed from the outlet 4. This etfects de-pressurization of the downstream chamber 14 to restore check valve 22 to the original position by virtue of the bias exerted thereon by spring 27. When valve 22 returns, closure of the system is attained.

CONSTRUCTION OF THE EMBODIMENT OF FIGS. 5 AND 6 Referring to FIGS. 5 and 6, a valve body 41 is provided at one end with threaded bore 43 communicating with an outlet 42 of a container. At the opposite end, the valve body is provided with external threads 44 for accepting a pipe (not shown). Within this externally threaded end portion, there is provided an internally threaded bore 45 of relatively large diameter. Bore 45 communicates with an internal valve chamber 46 of smaller diameter than bore 45. The valve chamber 46 has an annular groove 47 in its center. Communication between the valve chamber 46 and the threaded bore 43 is effected by a fluid introductory bore 48. Bore 48 has a shoulder 49 for supporting a spring 69. A snapring 50 is projectingly attached in the groove 47 as an abutment for an out-flow check valve member 57 (hereinafter referred to merely as check valve 57). A valve abutment 51 is provided with external threads 52 which engage with the threaded bore 45. Abutment 51 is also provided with an end portion 53 of smaller diameter than .that of the valve chamber 46. The end face of the portion 53 has an opening leading to an outlet or outlet passageway 55 via a downstream chamber 54. In addition, end portion 53 has an appropriate number of apertures 56 in the outer surface. Slightly downstream of the apertures 56, there is provided a packing 62 to seal the abutment 51 against the valve body 41. The abutment 51 is threaded in the bore 45 such that the narrow diameter end portion 53 is positioned in faceto-face relationship with the valve chamber 46.

Check valve 57 has an appropriate number of grooves 58 in its outer surface to permit the flow of fluid therethrough in either direction. One end of check valve 57 is provided with a shoulder 59 for supporting a spring 70. The opposite end of valve 57 is provided with a depression 60 for receiving a packing 61. Check valve 57 is slidably mounted between the snap ring 50 of the valve chamber 46 and the abutment 51. Check valve 57 is so positioned that the packing 61 assumes a face-to-face relationship with the fluid inlet passageway 48.

An in-flow check valve member 63 (hereinafter referred to merely as check valve 63) is provided with an annular groove 64. Check valve 63 is provided with a central bore 65 for permitting the flow of fluid therethrough. Bore 65 has a shoulder 66 for retaining a spring 69 around the bore opening. Check valve 63 has a projecting end 67, and has an external annular groove 64 into which a sealing ring 68 is fitted. Check valve 63 is slidably mounted between the snap ring 50 of the valve chamber 46 and the fluid inlet passageway 43. The projecting end 67 of check valve 63 normally abuts the packing 61 of check valve 57. The contacting faces between check valve 63 and the inside wall of the valve chamber 46 are effectively sealed by sealing ring 68. The check valve 63 is subjected to the urging of the spring 69, which spring is supported on shoulders 49 and 66. Spring 69 urges check valve 63 towards the fluid outlet passageway 55 and into abutment with the i stop 50.

Spring 70 is of slightly lesser strength than spring 69, and is supported between the shoulder 59 of the check valve 57 and the bore 54. The check valve 57 is subject to the urging of the spring 70 towards the check valve 63. Thus, the packing 61 of check valve 57 is urged into engagement with the projecting end 67 of the check valve 63 to block the bore 65. In actual practice, the valve body 41 is threadably engaged with the fluid outlet 42 of the container (not shown), and is coupled to a fluid discharge pipe (not shown) by means of threads 44.

OPERATION OF THE EMBODIMENT OF FIGS. 5 AND 6 The embodiment illustrated in FIGS. 5 and 6 operates as follows:

In FIG. 5, check valves 57 and 63 are shown in sealing contact with each other. The valves will assume this position when pressure is equal between the upstream and the downstream section. With the valves so positioned, no flow of fluid is permitted in the system. When a hand cock is opened to permit the flow of fluid out of the container and into the system, the upstream chamber 71 becomes highly pressurized. This causes the weaker spring 70 to retract, thereby disengaging the check valve 57 from the check valve 63. Thus the pressurized fluid from the container may now flow through the upstream chamber 71, the central bore 65, the cell 72, apertures 56, the downstream chamber 54, and the outlet passage 55, to finally emerge from the threaded bore 45.

As the hand cock is closed, the pressure in the intermediate bore 65 is reduced, thereby restoring the spring 70 to its original condition. Thus check valve 57 returns to its original position in sealing engagement with check valve 63. When valve 57 has completely returned, the flow of fluid is totally suspended in the system. When the hand cock is left open, intentionally or accidentally, check valve 57 will automatically move into sealing contact with check valve 63 as the fluid pressure in the container drops below a given value, which value is controlled by the strength of the spring 70. A sufficient reduction of pressure in the container will, of course, serve to totally suspend the flow of fluid in the system.

When a high pressure fluid supply pipe 33 is connected to the threaded outlet 45 of the valve body and the hand cock is opened to re-fill the container, the pressurized fluid will initially be introduced into the downstream cell 72 via the threaded bore 45, the outlet passageway 55, and the downstream chamber 54. The pressurized fluid urges check valve 63 in the upstream direction against the bias of spring 69. Check valve 57, however, is prevented from moving an appreciable distance in the same direction by the snap ring 50. Thus, the introduction of pressurized fluid from the supply pipe will effect separation of valves 57 and 63 to produce a gap therebetween. Thus, the supply fluid may flow through the intermediate bore 65, the inlet passageway 48, and finally into the container. When, after re-filling has been finished, the fluid pressure in the downstream cell 72 is reduced below a value commensurate with the strength of the spring 69, check valve 63 is again urged into sealing contact with check valve 57 by the spring 69, thereby blocking any further flow of fluid in the system.

OVERALL SYSTEM The embodiment of the valve unit as illustrated in FIG. 1 is constructed so as to be unitary with the fluid container. This valve unit can, however, be constructed as a separate unit. Likewise, the embodiment of the valve unit illustrated in FIGS. 5 and 6 is shown as a separate unit, but it can be made part of the fluid container. Alternatively, either embodiment can be incor-. porated in the inlet of a hand valve for the container.

As is evident from the foregoing, the fluid may flow in either direction in the system, until the check valves are automatically closed in response to a reduction of fluid pressure in the system below the predetermined value. In this way, the content of the container is kept free from the detrimental intrusion of air, dirt, oil, fumes, vapors, or other foreign matter.

What is claimed is:

1. A pressure responsive valve comprising:

a. a valve body;

b. a fluid inlet at one end of said valve body and a fluid outlet at the other end thereof;

c. a chamber in said body;

d. a first moveable valve member of generally annular configuration disposed in said chamber, said first valve member havingan annular boss extending therefrom and having a central bore therethrough defining a first fluid passageway through which fluid may bypass said first valve member,

said first valve member also having a separate, annular packing member attached thereto in contiguous relationship therewith, said annular boss extending through said annular packing member to secure said packing member in place;

e. a second moveable valve member disposed in said chamber, said second valve member having means on its outer surface defining a second fluid passageway through which fluid may bypass said second valve member;

f. said first valve member having means on its outer surface defining a third fluid passageway through which fluid may bypass said first valve member;

g. a first biasing means urging said first valve member toward said second valve member; and

h. a second biasing means urging said second valve member toward said first valve member, whereby said first and second valve members are urged into positions of mutual sealing contact.

2. A pressure responsive valve as: defined in claim 1,

wherein:

a. said first valve member is disposed upstream with respect to said second valve member; and

b. said annular boss has a portion extending beyond said packing member in a downstream direction.

3. A pressure responsive valve as defined in claim 2, wherein said extending portion of said boss has a radially outwardly protruding lip thereon for securing said packing member to said first valve member.

4. A pressure responsive valve as defined in claim 3,

wherein said second valve member has a side which faces upstream, said upstream side having a cylindrical recess therein, said extending portion of said boss of said first valve member being disposed within said cylindrical recess of said second valve member when said first and second valve members are in mutual sealing contact.

5. A pressure responsive valve as defined in claim 4, including:

a. a first annular projecting element in said chamber, said projecting element being connected with said valve body; and

b. a second annular projecting element on said upstream side of said second valve member, said first and second annular projecting elements both being sealingly engagable with said packing member.

6. A pressure responsive valve as defined in claim 5, including an abutment member in said chamber, said abutment member being removeably coupled within said valve body, said abutment member having an end face which faces in an upstream direction, said first annular projecting element extending from said end face, said abutment member having a bore therethrough, said second valve member being slideably disposed within said bore of said abutment member, said second biasing means being coupled between said abutment member and said second valve member.

7. A pressure responsive valve as defined in claim 1 wherein one of said biasing means exerts a greater bias than the other.

8. A pressure responsive valve as defined in claim 1 wherein said first valve member is disposed upstream with respect to said second valve member, said first biasing means exerting a greater bias than said second biasing means.

9. A pressure responsive valve as defined in claim 1 wherein said first and second valve members are slidably mounted in said chamber.

10. A pressure responsive valve as defined in claim 9, wherein said means defining said third fluid passageway includes a plurality of grooves disposed parallel to the axis of said first valve member.

11. A pressure responsive valve as defined in claim 10, wherein said means defining said second fluid passageway includes a plurality of grooves disposed parallel to the axis of said second valve member.

12. A pressure responsive valve as defined in claim 1 wherein said first fluid passageway is closed by the sealing engagement of said first and second valve members. 

1. A pressure responsive valve comprising: a. a valve body; b. a fluid inlet at one end of said valve body and a fluid outlet at the other end thereof; c. a chamber in said body; d. a first moveable valve member of generally annular configuration disposed in said chamber, said first valve member having an annular boss extending therefrom and having a central bore therethrough defining a first fluid passageway through which fluid may bypass said first valve member, said first valve member also having a separate, annular packing member attached thereto in contiguous relationship therewith, said annular boss extending through said annular packing member to secure said packing member in place; e. a second moveable valve member disposed in said chamber, said second valve member having means on its outer surface defining a second fluid passageway through which fluid may bypass said second valve member; f. said first valve member having means on its outer surface defining a third fluid passageway through which fluid may bypass said first valve member; g. a first biasing means urging said first valve member toward said second valve member; and h. a second biasing means urging said second valve member toward said first valve member, whereby said first and secoNd valve members are urged into positions of mutual sealing contact.
 2. A pressure responsive valve as defined in claim 1, wherein: a. said first valve member is disposed upstream with respect to said second valve member; and b. said annular boss has a portion extending beyond said packing member in a downstream direction.
 3. A pressure responsive valve as defined in claim 2, wherein said extending portion of said boss has a radially outwardly protruding lip thereon for securing said packing member to said first valve member.
 4. A pressure responsive valve as defined in claim 3, wherein said second valve member has a side which faces upstream, said upstream side having a cylindrical recess therein, said extending portion of said boss of said first valve member being disposed within said cylindrical recess of said second valve member when said first and second valve members are in mutual sealing contact.
 5. A pressure responsive valve as defined in claim 4, including: a. a first annular projecting element in said chamber, said projecting element being connected with said valve body; and b. a second annular projecting element on said upstream side of said second valve member, said first and second annular projecting elements both being sealingly engagable with said packing member.
 6. A pressure responsive valve as defined in claim 5, including an abutment member in said chamber, said abutment member being removeably coupled within said valve body, said abutment member having an end face which faces in an upstream direction, said first annular projecting element extending from said end face, said abutment member having a bore therethrough, said second valve member being slideably disposed within said bore of said abutment member, said second biasing means being coupled between said abutment member and said second valve member.
 7. A pressure responsive valve as defined in claim 1 wherein one of said biasing means exerts a greater bias than the other.
 8. A pressure responsive valve as defined in claim 1 wherein said first valve member is disposed upstream with respect to said second valve member, said first biasing means exerting a greater bias than said second biasing means.
 9. A pressure responsive valve as defined in claim 1 wherein said first and second valve members are slidably mounted in said chamber.
 10. A pressure responsive valve as defined in claim 9, wherein said means defining said third fluid passageway includes a plurality of grooves disposed parallel to the axis of said first valve member.
 11. A pressure responsive valve as defined in claim 10, wherein said means defining said second fluid passageway includes a plurality of grooves disposed parallel to the axis of said second valve member.
 12. A pressure responsive valve as defined in claim 1 wherein said first fluid passageway is closed by the sealing engagement of said first and second valve members. 